#1629

[@ebrombaugh]

Long ago I worked for a defense contractor and we used these to analyze radar pulses. The log envelope gives you a nice AM video signal for timing analysis and the limiter output can be analyzed for frequency.

[@hardlygamaliel455]

I used a cousin of this part (AD640) in a signal processing chain that started with a photomultiplier tube and ended with a PLL. The AD640 limiter output fed an almost constant amplitude signal to the PLL, resulting in an incredible dynamic range. Believe it or not, you can dig out an optical signal where each pulse of light consists of less than a dozen photons.

[@IMSAIGuy]

I worked on CMOS imagers and the small size pixels don't hold that many photons (converted to holes). Some 10bit A/D conversions of those pixels equate to one bit of voltage per photon.

[@stefflus08]

This was extra fun, watching you explore a chip you didn't know yet.

[@byronwatkins2565]

"That kink right there" is merely noise in ONE data point. Ignore the point at 70dBm and that kink moves to 80 dBm where the part's noise floor is about as big as the signal. Electric charge is conserved -- or Kirchhoff's current rule demands that the current have a destination. Omitting one pullup opens up the current path so no current flows in either path slice.

[@davidknightaudio934]

yep

[@brianharper9798]

Had a play with some AD8307 (similar chip I think), a directional coupler and an arduino. Trying to make a SWR meter, but never got it to work quite right.

[@MaxPivovarov]

How linear is the frequency characteristic? I think this module can be used as an input cascade for a power meter/frequency meter. Just add to it the frequency divider and Arduino for calculations.

[@t1d100]

I would love for Emsai Guy to do an Arduino project with this chip... To learn more about the chip's operations, uses and configurations. Please.

[@egirland]

Hi! Nice video, guy. What about the RSSI output? I cannot manage to get it working. Stuck @1.23V whatever RF power I apply to the input terminal. Tried -60dBm to -20dBm @30MHz.

[@egirland]

I reply myself: the power supply voltage was too low (+5V) so the internal voltage regulator (78L05) was not regulating. Rising power voltage to ~8Volt solved the problem. Thanks.

[@IMSAIGuy]

glad I could help 😎

[@Bruce-f2r]

Love your Videos say i was looking for a OP-Amp TLO84 Diode Log Amp and how get it to convert a RMS to a Log output signal can you do a video on OP-Amp Log Amps and how to RMS to Log signals Output thanks Bruce

[@IMSAIGuy]

I've been wanting to do a log amp video. someday. here is a chip of the day RMS: kzbin.info/www/bejne/jIWUmYaZfLaCrLMsi=2qAbE7ipMx8733bd

[@ploegmma]

Nice but expensive

[@IMSAIGuy]

expensive on mouser or digikey. $2.82 on aliexpress. I have no idea why

[@ploegmma]

@@IMSAIGuyoh wow! I can not imagine they counterfeit such chips.

[@shruthidhara5493]

Being a student i need a detailed explanation for each and every topic start from very basics 🙂

[@Siskiyous6]

Yup

[@t1d100]

Agreed. This outside of my knowledge base, so I had trouble following along. I would also like an expansion to its described uses.

[@IMSAIGuy]

This is a review of a particular part. If you don't follow this then obviously you won't be needing to use this part. I understand viewers are at all levels and try to create the spans this. I have 1600 videos so do watch some others and maybe come back to this one. I do a lot of RF engineering which you must be lacking. learn about power units of dBm and RF amplifiers.